package com.boarsoft.common.util;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class DESEnCoder {

	// 定义加密算法，有DES、DESede(即3DES)、Blowfish
	private static final String Algorithm = "DESede";
	public static final String CRYPT_KEY = "scrcu";
	public static final String CLIENT_KEY = "scrcu01";

	public static String encrypt(String text,String clientKey) throws IOException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException {
		return Base64.encode(encrypt(text.getBytes(),clientKey));
	}

	/**
	 * 加密方法
	 * 
	 * @param src
	 *            源数据的字节数组
	 * @return
	 * @throws BadPaddingException
	 * @throws IllegalBlockSizeException
	 * @throws InvalidKeyException
	 * @throws NoSuchPaddingException
	 * @throws NoSuchAlgorithmException
	 * @throws UnsupportedEncodingException
	 */
	public static byte[] encrypt(byte[] plaintext,String clientKey) throws IllegalBlockSizeException, BadPaddingException, InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException,
			UnsupportedEncodingException {
		StringBuilder key = new StringBuilder(CRYPT_KEY);
		if (clientKey == null) {
			key.append(CLIENT_KEY);
		}else {
			key.append(clientKey);
		}
		long time = System.currentTimeMillis()/1000;
		key.append(time);
		SecretKey deskey = new SecretKeySpec(build3DesKey(key.toString()), Algorithm); // 生成密钥
		Cipher c1 = Cipher.getInstance(Algorithm); // 实例化负责加密/解密的Cipher工具类
		c1.init(Cipher.ENCRYPT_MODE, deskey); // 初始化为加密模式
		return c1.doFinal(plaintext);
	}

	/**
	 * 根据字符串生成密钥字节数组
	 * @param keyStr 密钥字符串
	 * @return
	 * @throws UnsupportedEncodingException
	 */
	private static byte[] build3DesKey(String keyStr) throws UnsupportedEncodingException {
		byte[] key = new byte[24]; // 声明一个24位的字节数组，默认里面都是0
		byte[] temp = keyStr.getBytes("UTF-8"); // 将字符串转成字节数组

		/*
		 * 执行数组拷贝 System.arraycopy(源数组，从源数组哪里开始拷贝，目标数组，拷贝多少位)
		 */
		if (key.length > temp.length) {
			// 如果temp不够24位，则拷贝temp数组整个长度的内容到key数组中
			System.arraycopy(temp, 0, key, 0, temp.length);
		} else {
			// 如果temp大于24位，则拷贝temp数组24个长度的内容到key数组中
			System.arraycopy(temp, 0, key, 0, key.length);
		}
		return key;
	}

}